This invention relates to a filter for use in medical procedures, more particularly, for use in laparoscopic or endoscopic surgery.
During some medical procedures, e.g., laparoscopic and endoscopic surgery, a suitable gas is introduced into the abdominal cavity to inflate the abdomen. The inflation of the abdomen tends to separate the interior organs and to provide an enlarged cavity within which to perform the surgery. For example, one or more trocars can be used to puncture the abdomen, and insufflation gas can be passed through at least one of the trocar(s) to inflate the abdomen. One or more instruments involved in the surgery, e.g., a laparoscope, scalpel, laser and/or electrocautery device, can be inserted through the appropriate trocar(s) as needed.
When a particular procedure requires cutting of tissues and/or blood vessels, lasers, ultrasonic tissue fragmentation devices and electrocautery devices can be used as they are easily manipulated, and produce relatively clean cuts Moreover, they have a cauterizing effect, thus limiting bleeding.
Once surgery is completed, the gas used to inflate the cavity is vented from the abdominal cavity. Additionally, since cutting with lasers, ultrasonic tissue fragmentation devices and electrocautery devices often produces vapor or xe2x80x9csmoke,xe2x80x9d that can cloud or obstruct the surgeon""s view of the operative site, the surgeon may vent gas (including smoke) during the surgery to remove the smoke from the abdominal cavity. For example, the surgeon may release a valve associated with a cannula communicating with one of the trocars and vent the smoke to the surrounding atmosphere. Alternatively, the smoke can be recirculated, e.g., withdrawn from one trocar and reintroduced into the abdominal cavity through another trocar.
However, the smoke can contain toxic, odiferous, and otherwise undesirable material (e.g., benzene, hydrogen cyanide, toluene, formaldehyde, carbon monoxide, viruses, bacteria, cells, and/or body fluids from diseased tissue of the patient) that, if released into the environment of the operating room, could expose the surgeon and the surgeon""s staff to a health risk. Additionally, the release or recirculation of this smoke (that can, for example, contain bacteria and/or viruses) can subject the patient to the risk of additional contamination, e.g., via absorption through the peritoneum, or by entering the body at a location other than the abdominal cavity.
Attempts have been made to filter some of the gas passed from the abdominal cavity of the patient. However, these filters have suffered from a number of drawbacks. For example, some of the filters are bulky, and interfere with the surgeon""s vision and/or the surgeon""s ability to move in and around the surgical site. The filters may be easily plugged, fail to remove sufficient undesirable material and/or may require a labor intensive effort (possibly requiring numerous steps) to operate. Special equipment (e.g., instruments, valves and/or evacuators) may have to be utilized with the filters. Alternatively, or additionally, the filters may be unsuitable for use with adjustable gas flow rates and/or gas flow rates of about 1 liter/min or more at standard insufflation pressure.
The present invention provides for ameliorating at least some of the disadvantages of the prior art. These and other advantages of the present invention will be apparent from the description as set forth below.
In accordance with an embodiment of the instant invention, a filter device for gas(es), preferably gas vented from a patient""s body cavity (e.g., during laparoscopic surgery) is provided comprising at least one flexible filter comprising a flexible filter element, wherein the filter device is arranged to allow gas to pass therethrough. For example, a surface of the flexible filter can provide a wall or side of the filter device, wherein gas passes from one surface of the flexible filter, through the filter, and through an opposing surface of the filter, wherein a wall or side of the filter device comprises the opposing surface of the filter.
In some embodiments, the filter device comprises a housing and at least one filter element, wherein at least a portion of the housing is flexible and allows gas to pass therethrough, the filter device being arranged to allow gas to pass through the filter element(s) and the flexible portion of the housing.
In another embodiment, the filter device comprises a housing and at least one filter element, wherein the filter element has an effective filtration area of at least about 12.9 cm2 (at least about 2 in2), the filter device being arranged to allow gas to pass through the filter element(s) and through a portion of the housing.
In some embodiments, at least a portion of the housing and/or the filter element is flexible. In other embodiments, the housing and the filter element are substantially inflexible.
In preferred embodiments, the filter device removes laparoscopic smoke and reduces odor as the gas passes through the device to the exterior of the housing.
Embodiments of the filter and filter device are suitable for use at any desirable constant or variable gas flow rate. Preferably, the filter device can be easily added to any suitable system (e.g., a system for use in laparoscopic surgery). In an embodiment, the filter device (that can be part of a set) allows one-handed gas flow adjustment.
Embodiments of the invention are particularly for use in surgical environments, especially for use in laparoscopic surgery, as they can allow the surgical procedure to be completed more quickly and/or cost efficiently, e.g., by reducing the amount of valuable surgeon-, nurse-, technician- and/or operating room-time needed for the procedure. Time savings are particularly advantageous, since, for example, as of 1999, at least one study has estimated the value of time in the operating room during laparoscopic surgery as well over $120 per minute.
In accordance with the invention, a gas filter (preferably a smoke filter) comprises a retentive member, i.e., it retains at least one undesirable material such as at least one of microorganisms (e.g., bacteria), viruses, cells, body fluids, aerosols and liquid droplets, and allows at least a portion of the gas to pass through the retentive member, wherein the gas is depleted of at least some level of the undesirable material(s). The retentive member may also retain or reduce the passage therethrough of other undesirable material such as at least one of benzene, hydrogen cyanide, formaldehyde, and toluene, and/or the member may reduce the passage of odor therethrough. The smoke filter comprises at least one porous substrate of any suitable nature, e.g., a porous medium such as a fibrous web, a membrane, combinations thereof, and the like. Typically, at least a portion of the smoke filter is flexible.
Typically, the gas filter comprises at least one smoke filter element comprising a porous retentive substrate, preferably a porous retentive medium. The porous substrate can have any suitable physical dimensions and typically will be in sheet form having two opposing sides (e.g., a first side and an opposing second side) with a central portion therebetween, wherein the pores in the porous substrate will generally enable fluid communication between the first and second sides of the porous substrate. Typically, the gas filter comprises a smoke filter element comprising at least one hydrophobic membrane (preferably a hydrophobic microporous membrane) and/or at least one hydrophobic fibrous medium, through which the fluid (e.g., gas) to be treated passes. The element has two opposing sides (e.g., a first side and an opposing second side, in relation to a fluid to be treated wherein at least a portion of the gas is passed through the element), with a central portion therebetween. The pores in the element generally enable fluid communication between the two opposing sides (e.g., between the first and second sides) of the element.
The smoke filter can have any suitable pore structure, for example, a Dioctyl Phthalate (DOP) smoke penetration rating, or a pore rating (e.g., ability to remove particles of a given size to a specified degree, as evidenced, for example, by bubble point). The smoke filter can have a pore structure that is uniform, substantially uniform, or it can vary in a continuous, a discontinuous, or a stepwise manner. For example, the smoke filter can have a graded pore structure. In some embodiments, the smoke filter includes a plurality of elements and/or layers wherein individual elements and/or layers have different pore structures, e.g., different pore ratings. For example, the smoke filter can comprise a smoke filter element having a plurality of layers wherein at least two layers have different pore ratings.
The smoke filter can include additional elements, layers, or structures, which can also be membranes, or other porous media. For example, in some embodiments, the smoke filter can include additional components that have different structures and/or functions, e.g., at least one of prefiltration, odor-reduction, support, drainage, spacing and cushioning. In some embodiments wherein the smoke filter includes one or more additional elements, at least a portion of each of the additional elements is flexible.
As used herein, the term xe2x80x9csmokexe2x80x9d includes gas (e.g., the insufflation gas), as well as some of the material and/or some of the by-products produced by the ablation of tissues and/or blood vessels (e.g., aerosols and droplets). Smoke can include additional material, such as at least one of bacteria and viruses.